The present invention is directed to an assay system for assessing whether a compound modulates the activity of an enzyme with a metallated active site. More precisely, the invention concerns a method whereby the compound is provided attached to a solid support and binding of an enzyme is assessed with and without the presence of metal.
The use of solid supported assays for binding is well known in the art. Various labeling methods are available whereby a compound bound to a solid support can be shown to be complexed therewith. Labels include fluorescent labels, dye labels, enzyme labels, and radioisotope labels. The labeling can be either directxe2x80x94i.e., the compound tested for binding to a ligand attached to a solid support may itself be labeled, or a secondary labeling event can be employedxe2x80x94e.g., a bound antibody may be detected by a labeled antibody from another species. Such means of detection are well understood.
The present invention takes advantage of these mechanisms to determine whether a compound will modulate the activity of an enzyme wherein the enzyme has a metallated active site. This is accomplished by testing the binding of the enzyme to immobilized compounds both with and without the presence of metal.
In one aspect, the invention is directed to a method to determine whether a test compound modulates the activity of an enzyme that has a metallated active site, which method comprises:
a) providing said test compound coupled to a solid support;
b) treating said solid support with the enzyme in metallated form;
c) determining as a positive result of b) that the enzyme binds to said solid support and as a negative result of b) that said enzyme does not bind to said solid support;
d) treating said solid support with said enzyme in a nonmetallated form;
e) determining as a positive result of d) that the enzyme binds to said solid support and as a negative result of d) that said enzyme does not bind to said solid support;
f) whereby a positive result in c) and a negative result in e) identifies said test compound as a modulator of said activity.
In particularly preferred embodiments, the method is used to determine whether a metalloprotease is modulated by a test compound and to ascertain a member of a library of compounds which will modulate the activity of such an enzyme.